A diagram from Bob Metcalfe's original memo explaining how Ethernet works.Photo by Palo Alto Research Center

Most people probably associate Ethernet with a simple cable cinched with phone-like jacks. But, Ethernet is so much more.

It is the foundation for global Internet access and undoubtedly the world's most-used connectivity technology. In the annals of "techdom," Ethernet is a very big deal.

"Ethernet ranks highly among those technologies that impact day-to-day life on a global basis," IEEE Standards Association writes on its Web site. "Data center networks, PCs, laptops, tablets, smartphones, and now the smart grid, smart meters, personal medical devices, the Internet of Things, connected cars, and more -- Ethernet touches them all in one way or another."

It was 40 years ago today that inventor Bob Metcalfe passed around a memo explaining just how Ethernet would work -- connecting multiple computers to one another to exchange messages over increasingly busy networks.

The Ethernet that Metcalfe, along with inventor David Boggs, came up with wasn't the first of such network protocols -- some preceded it, and many more followed. But it won out to become the dominant local area networking (LAN) technology used for the Internet.

Over the years, Ethernet technology has evolved, expanded, and increased in speed. It's gone from an algorithm to complicated technology applied by dozens of companies aiming to create a better Internet experience for the world's users.

Giving an insider's view into the history of Ethernet, Metcalfe answered questions about the technology in one of Reddit's Ask Me Anything (AMA) sessions on Tuesday.

"You're probably connecting to reddit through a technology I invented," Metcalfe said to start off the AMA. "I'm Bob Metcalfe and I invented Ethernet."

He touched on topics such as his preferred color of Ethernet cable (yellow) and his love of the Internet: "I give the Internet credit for everything good that has happened since 1969."

He also talked about his admiration for Bill Gates and his enthusiasm about Google Fiber adding to the high-speed Internet competition.

When asked whether the Internet has exceeded his expectations, Metcalfe exclaimed: "By far, more each year, who would have guessed? We were building our own tools, and they escaped to serve uses unimagined."